Appearance: Empty Stroke blocks Fill
When applying a colour to a selection, sometimes this has no effect. While both the Color and the Appearance panel reflect the chosen colour, the object doesn't.
Most of the time the (unlogical) cause seems to be a Stroke without colour.
When changing the order in Appearance to having the Fill on top, the colour appears.
Please make an uncoloured stroke of no influence on underlying fills.
Jan Vork shared this idea